1. Field of the Invention
The present invention relates to a keypad for an electronic device and a manufacturing method thereof. More particularly, the present invention is related to a keypad for a folder-type portable telecommunication device and to a manufacturing method thereof.
2. Description of the Related Art
In general, a portable telecommunication device refers to a device that provides wireless communication with another party, while carrying the device. Such a portable telecommunication device includes a hand held product (HHP), a CT-2, a cellular phone, a digital phone, a personal communications service (PCS) phone, a personal digital assistant (PDA) or the like, which may be classified into various types depending on shapes or appearances thereof. For example, portable telecommunication devices can be classified into a bar-type, a flip-type, a folder-type, or a slide-type according to its appearance. The conventional portable telecommunication devices such as those listed above are typically provided with an antenna, a data input/output unit, and a transmitting/receiving unit or the like. As for the data input/output unit, a keypad capable of inputting data by typically pushing the keys with a user's fingers has come into wide-spread use. FIG. 2 shows an example of a conventional keypad of this type.
Generally, the folder-type portable telecommunication device includes a main housing; a folder being rotated in a longitudinal direction from or toward the main housing; and a hinge for enabling the folder to be rotated.
However, the conventional folder-type portable telecommunication device has drawbacks in that it is inconvenient to watch television or movies through the screen of the display part of the folder for a long time since the folder is configured to be only opened in a lengthwise direction, i.e., a longitudinal direction thereof.
In order to solve some of the drawbacks as described above, there is provided a Korean Laid Open Patent Publication No. 2005-104836, which discloses constructions of a conventional double axis hinge-type portable telecommunication device in detail.
As shown in FIGS. 1 and 3, the folder 2 of a double axis hinge-type portable telecommunication device 1 can be rotated in a transverse or longitudinal direction according to a use mode selected by the user.
When the display part 3 of the folder 2 is opened in the longitudinal direction as in FIG. 1, it is easy to input letters using a keypad 4. However, it has still drawbacks in that when the display part 3 is rotated and disposed in the transverse direction as in FIG. 3, the key inputting operation becomes more difficult because the letters formed on the keypad 4 are arranged in the longitudinal direction, not in the transverse direction.
To solve the above drawbacks, as shown in FIGS. 1 through 5, there has been developed a sliding keypad 5, which can change the arrangement of the letters in accordance with the opening direction of the folder 2 by sliding the letter sheet of the keypad 4 when the folder is opened in the longitudinal (FIG. 2) or transverse direction (FIG. 4), i.e., a direction perpendicular to the longitudinal direction of the device (referred to as a “perpendicular direction” hereinafter).
Referring now to FIG. 6, the conventional sliding keypad 5 includes a dummy film layer 5a, a first double-faced tape layer 5b, and a main sheet layer 5c having a upper surface with a UV and a vapor deposited rear surface, a sliding sheet layer 5d, a film layer 5e providing a space for the sliding sheet layer 5d, a second double-faced tape layer 5b, and a film layer for forming a UV contact point.
The conventional sliding keypad 5 with the construction shown in FIG. 6 becomes worn down due to the friction with the main sheet layer and other components when the sliding sheet layer slidably moves. In addition, the thickness of the keypad increased because of its multi-layered construction, which lessens a feeling of a “click” when the user presses down the keypad. Furthermore, cracks are easily formed more easily in the upper layer of the keypad due to its high hardness.
Hence, there has been a need to develop a keypad for an electronic device with improved construction and usability than known heretofore.